If I could take any pitcher to retire any batter at any point in the history of baseball, I might choose Aroldis Chapman at present. If I had to choose the worst pitcher in MLB in late May, I might have chosen Aroldis Chapman. Chapman didn't allow a run in his first dozen innings of the year, but in his subsequent four appearances, he allowed ten runs while recording four total outs. Over that stretch he walked 12 of the 19 batters he faced, bringing his seasonal line to 20 walks in 13 innings. Chapman was sent to the minors, but at some point he figured things out. Since being recalled in late June, Chapman has tallied 41 strikeouts compared to eight walks in 23.1 innings. I compared the PITCHf/x data of Bad Chapman (April/May) to Good Chapman (June-Present).

Baseball's best basestealers should get proper credit for knowing when crime does and doesn't pay.

We’ve heard the argument against RBIs a million times. It begins with name-calling and ends with being called names, but in between, the rational party explains that Runs Batted In do not control for context. Batters do not get to choose when they hit with runners on base. The same logic can be applied to win probability added—a measure that assigns credit based on the shift in a team’s win expectancy over the course of play.

A walk-off grand slam in a tie game might be worth 4 RBI and raise the team’s win expectancy to 100%, but the batter does not deserve more credit for that home run than for most other home runs. In fact, a single would have been just as good. Batters can alter their situational hitting but not their hitting situations. The accepted solution* has been linear weights, which gives batters credit for their contributions devoid of any context. An average home run is worth 1.4 RBI or 0.14 WPA.

Evaluating each pitcher who appeared in the Futures Game and identifying the most similar current major-league pitchers and pitches with the aid of PITCHf/x.

Sample size or apple pies? You can choose only one. Apple pies—that’s what I thought. A quick glimpse of a prospect might not tell us all we need to know, but it’s still plenty tempting to draw possibly premature conclusions. With that in mind, I decided to watch the Futures Game for the second straight year and make snap judgments on every single pitcher, even though none of them threw more than a couple dozen pitches. Last year, my main takeaway was that Zach Britton was the man. He still is. This year, I came to the conclusion that the only way to top a Bernie Williamsrendition of the national anthem is to catch a Sal Fasanofirst-base coach sighting.

The following table lists every pitcher who appeared in the game, in order of appearance. I’ll tackle them one by one, offering comps to current major leaguers where applicable, as well as links to videos of similar pitches.

Enlisting a new type of analysis to reveal who's winning the eternal battle between batters and pitchers, and why.

Background: You’ve got to admit they’re getting better

“When the 100-meter freestyle is held today in high school girls’ regional swimming meets, it is generally won by a girl who swims the distance in just under 60 seconds. That time would have won the men’s Olympic competition in 1920, or any year before it.”—Baseball Between The Numbers

Jeremy finds out whether the consistency of release points matters on a pitch-by-pitch basis and pinpoints the pitchers who give batters the same look most and least often.

Back in November, Mike Fast covered most everything you need to know about pitchers’ release points. The difficulty lies in determining the value of release point consistency. Mike found that pitchers with lower variation in their release points from game to game tended to produce lower walk rates, but looking at the distance between successive release points can also provide useful information at a more granular level.

With that in mind, I looked for all consecutive pitches from one pitcher to one batter and came up with the initial position of each pitch 50 feet from home plate, according to PITCHf/x, and each pitch’s run values using the process detailed here. The sample has some biases: all plate appearances must go at least two pitches, and curveballs will appear to be released higher than preceding fastballs, even if that’s not the case. This method does remove a significant bias that often exists when doing PITCHf/x analysis—miscalibration.

When in the season do most valuable players tend to debut, and what can consecutive Opening Day starts reveal?

Armed with a WARP database, I trekked back to my debut article on MLB debuts. Here are the dates on which a group of players worth at least 100 career WARP debuted, as well as the names of the players who contributed the most to those totals:

Jered Weaver is off to the best start of any pitcher in baseball, prompting Jeremy to examine how he's doing it and whether we can expect it to continue.

It seems as if every April there’s a pitcher who bursts upon the scene and makes us ask: How could he—how could anyone—be this good? Three years ago it was Cliff Lee, redefining himself as baseball’s top control artist. The following year it was Zack Greinke, a pitching prodigy who cleared his mental hurdles in order to become a pitching savant. Last April it was Ubaldo Jimenez’s turn, as the Rockies right-hander fully harnessed his fastball, the hardest pitch thrown by any starting pitcher. This year it’s Jered Weaver, off to a 6-0, 0.99 ERA start. But why him and why now?

Weaver has always been good. He began his MLB career in 2006 by winning his first seven starts. In 2009, he became the undisputed ace of the Halos’ rotation, and last year, he led all of baseball in strikeouts. Yet, the southern-California native had never captured the national spotlight before this season. Perhaps his fastball, just 90 miles per hour, failed to captivate our imaginations. Using more advanced PITCHf/x data, we can take a look at what makes Weaver so effective.

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The mysterious art of scouting needn't defy analysis, as long as ratings are applied consistently.

Consistency: the word itself a food metaphor, irony dripping from it like ice cream from a half-melted cone. Despite the rhetoric, consistency doesn’t matter much in baseball. What matters is being good. In the process of evaluating ballplayers, however, consistency is all that matters.

Scouts grade prospects based on a 20-80 scale where 50 is average, and, according to one scout*, “one grade is a standard deviation. Think of it as a bell curve.”

Reliving some of history's most unusual comebacks through the lens of win expectancy.

Had there been an unlikely comeback on yesterday’s slate of games, it would have served as the subject of my lead-in. Since no teams were kind enough to supply one, let’s forgo a lead-in and dive right into the wacky world of win expectancy. Baseball Prospectus houses win expectancy tables for all years over the Retrosheet Era (1954-2010), and The Hardball Times provides a Win Probability Inquirer that uses a theoretical model. I sifted through Retrosheet data to dig up some tidbits on historical win probability, focusing on some of history’s most improbable comebacks.

There have been 4,000 instances since 1954 in which a team has trailed by four runs with nobody on and two outs in the top of the ninth inning. Not once has a team come back from that deficit. According to theoretical win expectancy, that should have happened several times by now. Another 5,000 attempts have been made down by 5 or 6 runs, but the away team still has yet to come through. On a more exciting note, let’s look at some long-shot teams that did rise to the occasion.

In an offseason packed with turmoil and turnover but bereft of big-money acquisitions, the Mets made one high-profile on-field move by swapping Carlos Beltran and Angel Pagan in the outfield. Even though Beltran still feels that he could play center, he offered to move to right field to save his knees and supplement his offense at the risk of losing defensive value:

Cracking the Opening Day lineup even once is an honor, but what can we learn from players who repeat in the same roles?

What makes Opening Day different from all other days? Every team is undefeated, and every crowd is a sellout. The sun is out (sometimes) and the grass is green. It’s a national holiday in the same vein as Columbus Day, but without all the messy genocide.

Winning a starting assignment on Opening Day is the goal of every major leaguer. On Opening Day, managers start players they feel give their teams the best chances to win not only on that day, but for the rest of the year. Those who play on Opening Day are not only healthy, but often in the best shape of their lives. They also don’t have arbitration clocks that can be manipulated by forcing exile to the minors until May or June.